Class Two Lever Examples

Class Two Lever

A lever could be something as simple as a wooden board with a ridge that freely rotates or moves on a pivot. The most common and popular lever can be found in many playgrounds: a see-saw or teeter-totter. They are found everywhere and it is one of the most useful simple machines. There are three classes of levers. The image below is an example of a Class Two Lever, sometimes called a Second Class Lever.

Examples of Class Two Lever:

All classes of levers have four basic parts:

Beam- The lever, a wooden plank or metal bar resting on the fulcrum.

Fulcrum- the pivot or the turning point.

Force- the effort or input needed to move the beam and load.

Load- the item or object being moved or lifted on the plank.

The Class of Lever is determined by the location of the load, fulcrum, and force.

In a Class Two Lever, the Load is between the Force and the Fulcrum. The closer the Load is to the Fulcrum, the easier the load is to lift. Examples include wheelbarrows, staplers, bottle openers, nut cracker, and nail clippers.

A great example of a Class Two Lever is a wheelbarrow. The dirt in a wheelbarrow is the Load, the Fulcrum is the wheel, and the Force is at the end of the handles where a person lifts it. When the dirt is spread out evenly, the wheelbarrow is balanced and not difficult to push and move from place to place.

However, if all of the dirt is moved to the front, the Load is then closer to the Fulcrum, which will make it easier to lift. If the dirt was moved closer to the force or back of the wheelbarrow, it would become more difficult to lift.

Some simple machines are made up of two Class Two Levers such as nutcrackers, staplers, and nail clippers. In the nutcracker below, both handles come together, the force, to break open the walnut, the load. The fulcrum is located at the end of the nutcracker were the handles are joined together. Notice how the parts are located similar to the image to the right.